pjax = pushState + ajax

Introduction

pjax is a jQuery plugin that uses ajax and pushState to deliver a fast browsing experience with real permalinks, page titles, and a working back button.

pjax works by grabbing html from your server via ajax and replacing the content
of a container on your page with the ajax'd html. It then updates the browser's
current URL using pushState without reloading your page's layout or any
resources (JS, CSS), giving the appearance of a fast, full page load. But really
it's just ajax and pushState.

We want pjax to grab the URL /page/2 then replace #pjax-container with
whatever it gets back. No styles or scripts will be reloaded and even the <h1>
can stay the same - we just want to change the #pjax-container element.

We do this by telling pjax to listen on a tags and use #pjax-container as the target container:

$(document).pjax('a', '#pjax-container')

Now when someone in a pjax-compatible browser clicks "next page" the content of #pjax-container will be replaced with the body of /page/2.

Magic! Almost. You still need to configure your server to look for pjax requests and send back pjax-specific content.

The pjax ajax request sends an X-PJAX header so in this example (and in most cases) we want to return just the content of the page without any layout for any requests with that header.

Here's what it might look like in Rails:

defindexif request.headers['X-PJAX']
render :layout => falseendend

If you'd like a more automatic solution than pjax for Rails check out Turbolinks.

For debugging purposes, you can intentionally disable pjax even if the browser supports pushState. Just call $.pjax.disable(). To see if pjax is actually supports pushState, check $.support.pjax.

Usage

$.fn.pjax

Let's talk more about the most basic way to get started:

$(document).pjax('a', '#pjax-container')

This will enable pjax on all links and designate the container as #pjax-container.

If you are migrating an existing site you probably don't want to enable pjax everywhere just yet. Instead of using a global selector like a try annotating pjaxable links with data-pjax, then use 'a[data-pjax]' as your selector.

Or try this selector that matches any <a data-pjax href=> links inside a <div data-pjax> container.

Events

All pjax events except pjax:click & pjax:clicked are fired from the pjax
container, not the link that was clicked.

event

cancel

arguments

notes

event lifecycle upon following a pjaxed link

pjax:click

✔︎

options

fires from a link that got activated; cancel to prevent pjax

pjax:beforeSend

✔︎

xhr, options

can set XHR headers

pjax:start

xhr, options

pjax:send

xhr, options

pjax:clicked

options

fires after pjax has started from a link that got clicked

pjax:beforeReplace

contents, options

before replacing HTML with content loaded from the server

pjax:success

data, status, xhr, options

after replacing HTML content loaded from the server

pjax:timeout

✔︎

xhr, options

fires after options.timeout; will hard refresh unless canceled

pjax:error

✔︎

xhr, textStatus, error, options

on ajax error; will hard refresh unless canceled

pjax:complete

xhr, textStatus, options

always fires after ajax, regardless of result

pjax:end

xhr, options

event lifecycle on browser Back/Forward navigation

pjax:popstate

event direction property: "back"/"forward"

pjax:start

null, options

before replacing content

pjax:beforeReplace

contents, options

right before replacing HTML with content from cache

pjax:end

null, options

after replacing content

pjax:send & pjax:complete are a good pair of events to use if you are implementing a
loading indicator. They'll only be triggered if an actual XHR request is made,
not if the content is loaded from cache:

Server side

Server configuration will vary between languages and frameworks. The following example shows how you might configure Rails.

defindexif request.headers['X-PJAX']
render :layout => falseendend

An X-PJAX request header is set to differentiate a pjax request from normal XHR requests. In this case, if the request is pjax, we skip the layout html and just render the inner contents of the container.

Response types that force a reload

By default, pjax will force a full reload of the page if it receives one of the
following responses from the server:

Page content that includes <html> when fragment selector wasn't explicitly
configured. Pjax presumes that the server's response hasn't been properly
configured for pjax. If fragment pjax option is given, pjax will simply
extract the content to insert into the DOM based on that selector.

Page content that is blank. Pjax assumes that the server is unable to deliver
proper pjax contents.

HTTP response code that is 4xx or 5xx, indicating some server error.

Affecting the browser URL

If the server needs to affect the URL which will appear in the browser URL after
pjax navigation (like HTTP redirects work for normal requests), it can set the
X-PJAX-URL header:

defindex
request.headers['X-PJAX-URL'] ="http://example.com/hello"end

Layout Reloading

Layouts can be forced to do a hard reload when assets or html changes.

First set the initial layout version in your header with a custom meta tag.